Q: Is it true that some women can tell they are pregnant before they have done a test?

A: Some women claim they know they're pregnant from the very moment of conception. This may be because of intuition or because they notice some symptoms. Others can't tell until weeks after they've missed a period.

This is unusual however, and most women begin to notice common signs of pregnancy a couple of weeks after a missed period.

The first and most reliable sign is a missed period or one that is very light. It's important to remember however, that periods can be missed for other reasons such as stress.

Conversely, some harmless bleeding can occur during early pregnancy.

As early as a week after conception you may feel the urge to urinate more frequently. This is due to the changing hormonal levels and later the pressure on your expanding uterus.

You may also feel bloated around the abdomen as a result of water retention. Your breast may become larger and feel tender, tingly and lumpy.

During pregnancy, the veins around the breasts often appear more prominent and the nipples can deepen in colour.

So-called morning sickness is a common sign of pregnancy but you might also feel sick or hungry at any time of the day or night.

You may also start to have cravings for unusual foods, such as pickled gherkins or celery and this may be an indication that you are pregnant.

You may suddenly go off drinks, such as tea, coffee or red wine, from early on in pregnancy. The effects of rising levels of progesterone can also cause unusual tiredness, as well as a change in bowel motions, which can be loose or constipated.

A peculiar metallic taste in the mouth can occur very soon after conception, but usually subsides later in pregnancy.

Taken from the forthcoming book: Fertility and Conception by Dr Karen Trewinnard, published by Carroll & Brown, price #12.99.